General Motors (GM) said years ago that it planned to take the lead in self-piloted vehicles by the end of the decade, and now, its keeping up with that goal by looking to release a nearly-autonomous vehicle by 2020.

GM showed off its "Super Cruise" system in a demonstration in Michigan last week. The system uses cameras and radar to steer the car, keeping it in between the lines on streets and highways.

This system is a result of other available tehnologies seen today, such as radar-guided cruise control and warning systems for when drivers start drifiting out of their lane. But Super Cruise takes it a step further by controlling the electric power steering.

The demonstration showed Super Cruise controlling a a Cadillac SRX SUV, and according to reporters in attendance, the technology looked good.

While the demo was a success, the autonomous steering system isn't ready for the road on a commercial level quite yet. Engineers say they still need to work on how the system reacts to road conditions, sensor reaction time, visibility of lane lines and interaction with the driver.

But engineers say the system could be ready by the end of the decade. It would initially appear in Cadillacs, but would likely be apart of the rest of the GM lineup later on.

Last week, Nissan said it will push aggressively to release an autonomous vehicle by 2020 as well. The automaker has been working with several colleges such as MIT, UC Berkeley, Carnegie Mellon, Stanford, Oxford, the National Institute of Advanced Industrial Science and Technology, Virginia Tech, and almost every major university in Japan to develop the autonomous technology.

Nissan wants the autonomous cars to be available across the model range within two vehicle generations and to have an affordable price for consumers.

But you would lose convenience points by waiting for a car, and you would have all the same inconveniences as a driven taxi - you couldn't leave all your stuff in the back seat, trunk, etc. It isn't just price that makes people own cars rather than take taxis.